This study highlights the effect of solvent polarity on the yield (Y%) and properties of oil extracted from Algerian sesame seeds. Extractions were carried out under Soxhlet conditions with the following solvents: hexane (Hx), ethanol (Eth), acetone (Ac), dichloromethane (Di), isopropanol (Iso), hexane:isopropanol (Hx:Iso), and chloroform:methanol (Chf:Me). The sesame oil yield obtained using different solvents ranged from 28.86 to 52.83%. Fatty acids and sterols analyses were performed by GC on capillary column. γ‐Tocopherol was the major tocochromanol compound detected by HPLC‐fluorescence. Fourteen fatty acids were identified, with the predominance of oleic and linoleic acids. The main sterol in sesame oil was β‐sitosterol, followed by stigmasterol, campesterol, and Δ5‐avenasterol which were present in lower concentrations. High correlations were found between arachidic, gadoleic, behenic, and lignoceric acids concentrations; these results were explained by the metabolic biosynthesis pathway of the biologically active long‐chain PUFA by successive elongation and desaturation. Principal component analysis (PCA) of the data obtained from sesame oil composition enabled an easy comparison of the different extraction solvents, and correlated their properties with the most characteristic components of the extracted oils with a view to understand solvent–oil interaction, and to establish the effects of extracting solvent on such oil composition.Practical applications: This study showed that the choice of solvent depends largely on the desired fraction to be extracted. Sesame oil was better extracted with less‐polar solvents but membrane‐associated lipids are more polar and require polar solvents capable of breaking hydrogen bonds or electrostatic forces. Owing to the differences in solvent capacity, the fatty acids, sterols, and tocopherols extracted along with the oil vary, leading to differences in the quality of the extracted oil. The results obtained in this study could be applied in industrial extraction to encourage the use of alternative extraction solvents.

Convolvulus austroaegyptiacus Abdallah & Sa'ad (CA) and Convolvulus pilosellifolius Desr. (CP) are commonly used in the Saudi Arabia folk medicine. They are potent in treating the ulcers and skin diseases. The lack of information about their biological activities led us to investigate the possible biological activities by determination of antibacterial and antioxidant activities of total ethanolic extracts and various fractions. Total flavonoid contents of the plants were determined by colorimetric method while total phenols were determined by using Folin-Ciocalteu method. In vitro antibacterial activity was studied against E. coli, P. aeruginosa, and B. subtilis, and the total antioxidant capacity was evaluated by radical scavenging method. IC50 were found to be 21.81, 17.62, and 3.31 μg/mL for CA, CP, and vitamin C, respectively, while the lowest MIC value of 0.25 mg/mL was recorded with CP extract against B. subtilis. Around 21 compounds are tentatively elucidated from both plants using rapid, simple, and high-resolution analytical technique for chemical profiling of natural compounds by direct analysis in real-time of flight-mass spectrometry, of which 17 were not isolated or reported previously.

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This work describes the preparation of polymer based monolithic materials and their use as stationary phases in capillary liquid chromatography. Multi-walled carbon nanotubes (MWCNT) were incorporated into a mixture containing benzyl methacrylate (BMA) and ethylene dimethacrylate (EDMA) as co-monomers. The optimized porogenic mixture was a ternary solution composed of cyclohexanol, 1,4-butandiol and butanol which resulted in a stable and homogeneous suspension. Six capillary columns with increasing amounts of MWCNT, from 0 to 0.4 mg mL(-1), were prepared by thermal polymerization in 0.32 mm (i.d.) and 150 mm length fused silica tubing. The chromatographic evaluation showed that the synthesized monolithic beds were mechanically stable while their porosity and permeability increased with the MWCNT content. The prepared capillary columns were tested for the separation of mixtures of ketones and phenols at an optimum flow rate of 2 μL min(-1). The results showed that incorporation of MWCNT slightly affected the retention while it enhanced the column efficiency by increasing the column efficiency by a factor of up to 9. This effect corresponded also to an improved resolution and full separation of the solutes.

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